Concrete gun



May 30, 1933. F. H. KERNAN CONCRETE GUN Filed Jan. 26, 1931 m N & 3 $1 3 Q l m U l I Q mum m V O M H A t C M Am -m yaw-m m E 0 E 5 Patented May 30, 1933 i UNITED STATES FREDERICK H. KERNAN, OF IRVINGTON, CALIFORNIA I concnn'rn eon Application filed January 26, 1931. Serial No. 511,424.

' This invention relates to pneumatic concrete placing apparatus or so-called concrete guns, particularly as used in the lining of tunnels with concrete.

The principal object of my invention isto p'rovideapparatus of this kind which will be more adaptable to tunnel work than prior apparatus of this kind, particularly in the feature of special construction whereby it is hung'low, to-the floor of the tunnel so as to permit of direct loading with the charge from an ordinary portable, cylindrical tilting concrete mixer carried on a fiat car rolled in on the same track on which the r gun is supported and behind the same.

Other features are the receivlng end con-' struction and traveling air jet operated from adjacent the ,charging end of the'gun and which progressively ejects the material from the nozzle at the forward endof the concrete container. I Further objects and features of construc tion will appear in the following specification and accompanying drawing.

In further detail the drawing shows, a Fig. 1 a side elevation of the concretegun asjin'place on a tunnel track and with a cylindrical concrete miXer discharging its load into the rear end of the gun.

Fig. 2 is an enlarged side elevation, partly in section, showing the traveling air jet aperture, and adjacent parts. i

Fig. 3s a crosssection of'Fi 2 taken along the line 33 thereof, and l ig. 4 is a plan view of the inner or revolving portion of the air nozzle showing the spiral air slit.

In further detail the apparatus comprises a concrete container formed of a horizontally disposed cylindrical portion 1 joined to an upwardly slanted portion 2 which may be'cylindrical' but is here shown as tapering to somewhat smaller diameter at its elevat ed end and where it is fitted with'an airtight door in the form of a disk'3 pivotally mounted at 4 to swing inwardly and upwardly as indicated in the heavier dotted lines to a closed position as'indicated in the lighter dotted lines. The pivot 4 of this door is a shaft passing through a suitable stufling box. to-the outside of the shell where it is secured to the end of a lever '5 and which lever is pivoted at its outer end to the piston rodG of an air cylinder 7 pivotally 1 supported at 8 to the side of the container shell, so that upon applying air pressure through either hose lines 9 and 10 controlled by valve 11 on air supply pipe 12, the door may be'opened orclosed. It is of course evident that this door may be opened man ually by means of'lever 5 if desired. A suitable gasket, not shown, is provided for, making the door air-tight when closed.

The container is provided with four wheels 18 rollable on the tunnel car tracks 14, and the forward end of the cylindrical portio'nl is provided with a funnel-shaped discharge spout '15 lyingsubstantially flush with the bottom of the container'and which spout terminatesas a pipe 16 adapted for connection to the concrete conduit ipipe through which the concrete is ejected to -position desired, such as in back of the lining forms for lining the tunnel.

The concrete is ejected by air" pressure from a tubular nozzle 17 which extends air-' tight through the upwardly slanted lower wall of rear section 2 of the container to lie along the bottom with its forward end terminating adjacent the spout 1 5, as dotted in Fig. 1. I v

This air nozzle is arranged with an innor revolving tubular piece 18 to which air is supplied under pressure from a pipe-19 and has a' spiral slot 20 in its upper wall which mav be revolved under astraight slot 21 in the outer wall of the outer tubular portion 17 '"ofthe nozzle so'as to effect a traveling air aperture as the'inner portion is revolved. To provide for accurate manufacture and to take up wear the members 17 and 18 are tapered and a tubular liner 22 is interposed. This liner is provided with a straight slot'23 on top in register with straight slot 21 in outer tube 17. Slot 21 is preferably slightly beveled outwardly as shown in Fig. 3'and covered with a piece of heavy wire-screen 24L preferably welded in place alon the edges, and spiral slot 20 terminates at both ends in a straight portion 20. 20- so that a longer full open slot may be had at each end of the spiral slot.

At the point of emergence of revolvable tube 18 from liner 22 is a stuifing box 25, and at the outer end of tube 18 is secured a bevel gear 26 meshed bv a pinion 27 secured to a shaft 28 carried along the under side of section 2 of the container and fitted at its upper end with a handwheel 29 for manuallv turning spirally slotted member 18 of the air nozzle.

Extending axially rearward from the outer end 18 of member 18 is a rod 30 carrying a loose handwheel 31 which may be grasped and bumped against a collar 32 fixed to the outer end of the rod, so as to loosen the long tapered nozzle sections in case they stick, or when desiring to remove them for cleaning or dressing.

, The construction of the gun with its lowdown body and upwardly slanted rear end was for the express purpose of end loading at the rear, and particularly from a tilting concrete mixer 33 as indicated in Flg. 1 wherein this mixer is carried on a wheeled truck 34 rolling on portable switch tracks 35 carried on flat cars as at 36 rollingalong the central tunnel tracks 14.

types, power-driven or not, and with any desired form of power dumping mechanism,

the toggles 37 being sufficiently indicative of such well-known construction.

By the arrangement shown it is possible to load the gun directly from the rear with a tilting concrete mixer or drum without conveyors of any kind as heretofore required, and besides this the design of the apparatus permits this to be done without requiring much head room, so that it is practicablegin small tunnels.

In operation the container is filled to a point just below the loweredge of the door opening, the door is closed, air under pressure is turned into the nozzle 18 fromhose the concrete from the forward end, of the container through spout 15, and the attendant then slowlv. or intermittently, turns the nozzle 18 to move the effective opening backward to successively pickoff the concrete from the forward end of the charge until it is all ejected. The slanted bottom of section 2 of the-container constantly feeds the char e downward and forward to the air jet. I s

Air pressure of course at once builds up in the whole container as soon as the advanced portion of the slot is opened to thus assist in the ejection of the mass from' all points, so that the traveling aperture successively cuts off as it were the material from theforward portion of the pile for ejection by the force of the air from all sides.

It is manifest without further drawings that the spiral slot in the air nozzle need not be continuous, but that it could be av series of holes along a spiral path, and therefore the terms slot or slotted used herein and in the claims are intended to cover such an obvious variation.

Also it is to be understood that while my apparatus is especially devised for the ejeczontally disposed cylindrical section joined to an upwardly slanted section, a. spout adj acent the bottom and at the end of the cylindrical section, and a charging door at the elevated end of the slanted section, I

2. Pneumatic ejecting apparatus comprising a receptacle having a substantially horizontally disposed cylindrical section joined to an upwardly slanted section, a spout adjacent the bottom and at the end of the cylindrical section, a charging door at the elevated end of the slanted section, means mounting said doorfor opening inwardly, and power-operated means for opening and closing said door.

3. In a pneumatic ejecting apparatus for concrete and the like, a receptacle provided with a dischargeopening at one end, an elongated tubular air nozzle'within the receptacle extending from a point adjacent said spout in a direction along the bottom of the receptacle, means for supplying fluid under pressure to said nozzle, said nozzle comprising inner and outer tubular members relatively rotatable, and vone of the members being longitudinally slotted and the other spirally slotted whereby upon turning them relatively an air emitting aperture maybe obtained at various points along said nozzle.

4. In a pneumatic ejecting apparatus for concrete and the like, a receptacle provided with'a discharge opening at 01166116., an elongated tubular air nozzle within the receptacle extending from a point adjacent said spout in a direction along the bottom of the receptacle, means forsupplying fluid under pressure to said .nozzle, said nozzle comprising inner and outer tubular members relatively rotatable, and onev of the members being longitudinally slotted, and the other spirally slotted whereby upon'turning them relatively an air emitting aper ture may be obtained at various points along said nozzle, and said spiral slot having straight end portions to coincide for adisunder pressure to said nozzle, said nozzle comprising inner and outer tubular members relatively rotatable, and one of the members being longitudinally slotted and the other spirally slotted whereby upon spiral slot arranged to cross the slot in the outer member and said sprial slot terminating at the end in a straight run to coincide with the slot in the outer member.

10. In a pneumatic concrete ejecting apparatus, a receptacle, an air ejecting nozzle along the bottom of the receptacle comprising an elongated tubular member and provided with a slot along its wall, an inner tubular member revolvably mounted within the first tubular member provided with a spiral slot arranged to cross the slot in the outer member and said spiral slot terminat ing at the end in a straight run at both ends turning them relatively an air emitting aperture may be obtained at various points along said nozzle, and manually-operated means for revolving the members relatively. 6. In a pneumatic ejecting apparatus for concrete and the like, a receptacle provided with a discharge opening at one end, an elongated tubular air nozzle within the receptacle extending from a point adjacent said spout in a direction along the bottom of the receptacle, means for supplying fluid under pressure to said nozzle, said nozzle comprising inner and outer tubular members relatively rotatable, and one of the members being longitudinally slotted and the other spirally slotted whereby upon turning them relatively an air emitting aperture may be obtained at various points along said nozzle, a gear at the end of one of said members, a pinion meshing said gear, a shaft to coincide with the slot in the outer mem- 80 ber.

FREDERICK H. KERNAN.

Wheel at the end of said shaft for revolving said one of said members.

7 In a pneumatic concrete ejecting apparatus, a receptacle, an air ejecting nozzle along the bottom of the receptacle comprising an elongated tubular member closed at one end and provided with means for escape of air for a distance along said member, a movable member within said tubular member arranged for changing the effective position of the air escape along said tubular member. r

8. In a pneumatic concrete ejecting apparatus, a receptacle, an air ejecting nozzle along the bottom of the receptacle comprising an elongated tubular member and provided with a slot along its wall, an inner tubular member revolvably mounted Within the first tubular member provided with a spiral slot arranged to cross the slot in the outer member, means for supplying compressed air to the inner member, and means for turning the inner member.

9. In a pneumatic concrete ejecting apparatus, a receptacle, an air ejecting nozzle along the bottom of the receptacle comprising an elongated tubular member and provided with a slot along its wall, an inner tubular member revolvably mounted within 7 65 the first tubular member provided with a V 133 to which said pinion is attached, and a hand- I I 

